On February 7th, the Who played the biggest gig of their 46-year career: a Super Bowl halftime show that saw the band chugging through a 12-minute medley of hits for an audience of more than 150 million viewers in 230 countries. But the Who’s Super Bowl show might also be one of the band’s last. Last fall, guitarist Pete Townshend‘s longtime struggle with tinnitus once again became an issue, leading to the cancellation of a planned spring 2010 tour. “If my hearing is going to be a problem, we’re not delaying shows,” Townshend says. “We’re finished. I can’t really see any way around the issue.”

But for one night, the Who put aside health concerns. At Sun Life Stadium in Miami, Townshend kicked off the band’s raw, loud set with the immediately recognizable opening chords to “Pinball Wizard.” Playing on a circular 140-foot stage, the band – Townshend and singer Roger Daltrey backed by guitarist Simon Townshend (Pete’s brother), keyboardist John “Rabbit” Bundrick, bassist Pino Palladino and drummer Zak Starkey – powered through portions of “Baba O’Riley,” “Who Are You,” “See Me, Feel Me” and, finally, “Won’t Get Fooled Again.” Directed by concert-film veteran Hamish Hamilton (U2, Britney Spears), the show featured the biggest barrage of lighting and pyro in the halftime’s history. With Townshend breaking out his trademark guitar windmills, the set built to a climax with the crowd of 72,000 shouting along with “Won’t Get Fooled Again.” “The Super Bowl puts on a great spectacle,” Daltrey says. “That’s just what they need at halftime.”

During the Who’s early tours of America, the group was dogged by what Townshend calls “the fucking Super Bowl.” “You come to America, and you’re going to show everybody how cool you are: ‘We’re here, we’re gonna smash our guitars!'” he recalls. “You get to the dressing room, and everybody is looking at the Super Bowl on TV. There was that sense of it being far more important than anything we might ever do.”

The Who’s journey to the halftime show – which has been played in recent years by Bruce Springsteen, Tom Petty, Prince and the Rolling Stones – began last June, when NFL executives contacted Who manager Bill Curbishley. Although neither Daltrey nor Townshend had ever attended a football game, they agreed to perform – both for the visibility and, Townshend says, “for a week in Florida in the sunshine.” Curbishley felt the show would be a way to make fans of the CSI franchise (which uses “Won’t Get Fooled Again,” “Who Are You” and “Baba O’Riley” as theme songs) realize who sang those songs. “People who are into the CSI music don’t register it with any particular band,” he says.

From the beginning, Townshend has been the Who’s principal songwriter, guitarist and guiding force. Yet in a sign of a greater level of cooperation between Townshend and Daltrey, Townshend ceded control of the halftime arrangement to his bandmate – allowing Daltrey to be the Who’s musical director for a night. “I’m not keen on medleys,” Townshend says. “But I had a sense Roger would be able to pull it off, and I think he did. It felt fairly smooth to me. Roger and I have a great relationship these days. It’s very warm and close.”

For such a high-profile gig, Townshend and Daltrey did a surprising minimum of prep work. Neither watched the DVD of past halftime shows supplied to them by the NFL. The full band didn’t begin rehearsing until the week before. Townshend did, however, contact friends in the Springsteen and Petty camps to ask how their performances went, as well as old friend Ron Wood. “Ronnie said it was over in a heartbeat,” he recalls.

The Super Bowl was intended to be the official kickoff for a busy season of Who activity. But last fall, Townshend informed Curbishley he wanted to spend more time working on material for his upcoming musical, Floss, about an aging rocker and his family. As a result, planned shows at Coachella and the New Orleans Jazz and Heritage Festival were scrapped, along with other possible dates. “I really don’t want to be on the road and have to drop this work I’m doing,” Townshend says. “I may never have the stamina to write another major piece that’s going to take me two or three years.”

An even bigger factor, though, were the hearing problems Townshend has been struggling with since the Seventies and that were recently exacerbated by the time he’s spent in the studio working on Floss. Last year, Neil Young put him in touch with an audiologist who recommended a new model of in-ear monitor, which would allow Townshend to hear the monitor mix at a volume low enough that it shouldn’t further damage his hearing. Although Townshend didn’t use them at the Super Bowl, he plans to put the monitors to the test during the group’s only scheduled concert in 2010: a March 30th charity performance of Quadrophenia in London. If the modules work, further Who dates could be scheduled for the fall. “It’s a good test of Pete’s hearing,” says Daltrey. “We won’t know until we try.”

In the meantime, Townshend says he emerged with surprisingly positive feelings about playing the halftime extravaganza. “It just flashed by,” he says. “I’ve had a lot of e-mails from people. The word they use most is ‘amazing,’ followed closely by ‘nice hat.'”